This study investigated whether calibration and discrimination are distinct or related aspects of probability judgment accuracy by examining the effects of two different training techniques. Participants received either performance feedback or environmental feedback, and we measured their improvement in calibration and discrimination as a function of feedback type. Whereas performance feedback reduced participants' overconfidence and environmental feedback improved discrimination, neither type of feedback led to an improvement on the other component. In fact, environmental feedback led to an increase in overconfidence. We take these results as evidence that calibration and discrimination are dissociable abilities that require separate training techniques for improvement. Copyright 2000 Academic Press.